The Contactless IC card has been adopted in numerous fileds and over the course of time has been widely used in connection with traffic, access control systems, and electronic payment, among other fields. In recent years, and in light of requirements in Mass Rapid Transit, Logistics Management, product Anti-counterfeiting, identity identification etc., Contactless IC card technology has experienced continuous improvements, and is being applied in increasingly diversified ways. Similarly, mobile devices have also seen rapid development, and are now carried by numerous people. Recent mobile devices have included RF ID technology. Specifically, a mobile phone may have an electronic payment function that integrates both RFID technology and mobile communication technology.
Near field communication (NFC) technology is a short-range technology for wireless communication, which conforms to the ISO/IEC 18092 and ISO/IEC 21481 standard, its operating frequency is 13.56 MHz, and its communication distance is cm-level. Electronic devices can perform Duplex service by using the NFC technology, and perform Contactless exchanging, digital data accessing and coupling to other NFC device through the single touch mode. That is, NFC technology is a technology that combines contactless identification and interconnection and, as such, it can also be regarded as one type of radio frequency identification (RFID) technology. NFC technology is deduced from the contactless smart card (CSC) technology, and it may conform to the ISO/IEC 14443 type A standard. Thus, an electronic device with NFC function may be a tool in the context of electronic payment in commercial trade.
The application of the NFC technology may be roughly divided into three types as follows:    1. Touch and Go Mode: applied to identity identification and electronic tickets, such as access control, login information system, document signing, card system, bus ticket or entrance ticket etc. The user only need to carry the NFC apparatus storing the identity identification data or the electronic tickets data close to the reading apparatus (such as a card reader). In addition, it can be used for data capturing, such as obtaining a website directly from a “smart poster.”    2. Touch and Confirm Mode: applied to mobile business payment system, the consumer uses the NFC apparatus for payment trade. Such an NFC apparatus may store the information of a credit card, Value Card or Electronic Purse etc., for electronic payment trading.    3. Touch and Connect Mode: applied to coupling between two NFC apparatus, for peer-to-peer (P2P) transmitting, such as music downloads, image exchange and address book synchronous processing etc.
FIG. 1 is a function block diagram of a mobile phone with NFC payment function according to the prior art. The mobile phone 10 comprises an antenna 110, a NFC IC 130, a security IC 150, a control IC 170 and a subscriber identity module (SIM) card 190. The security IC 150 is used for storing authentication data, and the control IC 170 and the SIM card 190 are used for phone operations.
When a user wants to perform an identification procedure in connection with an electronic payment, the mobile phone 10 is brought close to a NFC card reader (not showing). The mobile phone 10 receives the data from the card reader by the antenna 110. Next, the NFC IC 130 performs the identification procedure according to the data transmitted by the card reader and the authentication data stored in the security IC 150, in the identification procedure, the NFC IC 130 can communicate with the card reader by the antenna 110, and transmits the authentication data stored in the security IC 150 to the card reader, for achieving electronic payment function.
Since the security IC 150 is fixed in the mobile phone 10 (so the user can't transform the authentication data stored in the security IC 150 to a new mobile phone), when changing the mobile phone, for example, the stored-value balance, the information of the Electronic Purse, the information of the access control, the information of the bank account and the information of the traffic ticket etc. are all unable to be transferred to a new mobile phone for seamless usage. In addition, the power of the NFC IC 130 is supplied only by the battery (not shown) of the mobile phone 10, such that the NFC IC 130 can not work when the battery is dead. For example, if the mobile phone 10 is used for traffic ticket, when the battery of the mobile phone 10 is dead, there will be trouble when performing the identification procedure of the electronic payment. Furthermore, there are no safety measures for preventing others to perform the identification procedure of the electronic payment, e.g., when the mobile phone 10 is lost. As such, there is a risk of theft as well.